Redefinition of the map position and validation of a major quantitative trait locus for fire blight resistance of the pear cultivar 'Harrow Sweet' (Pyrus communis L.)

Pierre-Marie F. Le Roux (1) , Danilo Christen (1) , Brion Duffy (1) , Stefano Tartarini (2) , Luca Dondini (2) , Toshiya Yamamoto (3) , Chikako Nishitani (3) , Shingo Terakami (3) , Yves Lespinasse (4) , Markus Kellerhals (1) , Andrea Patocchi (1)

1 Agroscope
2 Dipartamento di Colture Arboree
3 National Institute of Fruit Tree Science
4 IRHS - Institut de Recherche en Horticulture et Semences

With 3 figures and 2 tables Abstract In a previous study, a QTL analysis was conducted on a pear F1 progeny derived from a cross Passe Crassane (PC) x Harrow Sweet (HS). Four genomic regions associated with fire blight resistance were identified, including two main QTL located on linkage groups (LGs), 2A and 4 of Harrow Sweet (HS02A and HS04). In the present study, we report the combination of LGs HS02A and HS02B into a single LG by mapping additional SSR loci from Malus or Pyrus spp. We could thereby precisely identify a single major QTL on LG HS02. We also confirm a putative QTL on LG HS04 by including new SSR markers to the pre-existing LG HS04. Based on SSR marker analysis of Harrow Sweet pedigree, the major HS02 QTL is presumed to originate from the cultivar Early Sweet, while the HS04 QTL was traced from Harrow Sweet back to Bartlett. We also describe the validation of the major HS02 QTL for the fire blight severity trait in a second F1 progeny derived from a cross Angelys x Harrow Sweet.

Mots clés: Pyrus spp; Malus spp; microsatellite; synteny; marker-assisted breeding; Erwinia amylovora; X-DOMESTICA BORKH.; MOLECULAR MARKERS; APPLE; LINKAGE; QTL; PROGENIES; SELECTION; MANAGEMENT; EFFICACY; GENOME

Domaines: Sciences du Vivant [q-bio]

Pierre-Marie F. Le Roux, Danilo Christen, Brion Duffy, Stefano Tartarini, Luca Dondini, et al.. Redefinition of the map position and validation of a major quantitative trait locus for fire blight resistance of the pear cultivar 'Harrow Sweet' (Pyrus communis L.). Plant Breeding, 2012, 131 (5), pp.656 - 664. ⟨10.1111/j.1439-0523.2012.02000.x⟩. ⟨hal-01209920⟩